1. Field of the Invention
The present invention relates to pigment extraction systems and methods, and, more particularly, to such systems and methods for use in color enhancement of juices.
2. Description of Related Art
An improvement in the color of a comestible or edible product is often sought in order to enhance the product""s visual appeal and, hence, marketability. Such products include fruit juices, including grapefruit juice.
The addition of highly colored pulp to grapefruit juice is known in the art (W. A. H. Huffman et al., J. Rio Grande Valley Hort. Soc. 7, 102-5, 1953; F. P. Griffiths and B. J. Lime, Food Technol. 430-32, 1959; B. J. Lime and F. P. Griffiths, J. Rio Grande Holt. Soc. 14, 88-93, 1960). It is also known to blend grapefruit juice with a highly colored grapefruit such as Star Ruby (R. R. Cruse et al., J. Agric. Food Chem. 27, 641-42, 1979; S. V. Ting et al., Proc. Fla. State Hort. Soc. 93, 293-95, 1980). It is further known in the art to apply a carotenoid bioregulator (H. Yokohama et al., Phytochem. 11, 1721-24, 1972) and to add artificial color (R. L. Huggart and S. V. Ting, Proc. Fla. State Hort. Soc. 83, 277-81, 1970).
The drawbacks of the previous methods known in the art include excessive bitterness, excess pulp content, limited fruit availability, and the juice negative connotations associated with the addition of foreign materials into the juice.
In a study with orange juice, an addition of chromoplasts from tangerines to orange juice (R. W. Barron et al., U.S. Pat. No. 3,725,083) was reported to improve color.
The process of Cohn (U.S. Pat. No. 3,037,975) includes removing aqueous liquors from citrus fruit peel, adjusting the pH, and heating the liquor to form a pasty product that contains flavoring and coloring substances. The method of Sperti (U.S. Pat. No. 3,385,711) involves the removal of a xe2x80x9cbitterness characteristicxe2x80x9d from the pulp of a citrus fruit that has a tendency to become bitter with time. Villadsen (U.S. Pat. No. 3,404,990) teaches an addition to citrus juice of peels and/or rags of citrus fruits. The method of Grant (U.S. Pat. No. 3,523,138), which is for extracting a xanthophyll product from marigold petal meal, includes an addition of alkali and aliphatic alcohol, followed by treatment with an inert organic solvent. Barron et al. (U.S. Pat. No. 3,725,083) describe the removal of xe2x80x9cchromoplastsxe2x80x9d from filtered juice by centrifugation to provide a material for adding color to other juices. The extraction method of Anderson (U.S. Pat. No. 3,906,112) includes the preparation of an oil extract of carotenoid pigment in crustacean shell waste. Johnson et al. (U.S. Pat. No. 4,126,709) and Howell et al. (U.S. Pat. No. 4,377,520) use oil from the flavedo of the fruit as a source of a carotenoid product. Epperson et al. (U.S. Pat. No. 4,608,266) teach a process for forming a citrus juice extender from the flavedo. The process of Ausich et al. (U.S. Pat. No. 5,858,700) is for producing lycopene crystals from oleoresin, and admixing the oleoresin with propylene glycol, alkali, and water to form a saponification mixture, which yields the desired crystals.
It is therefore an object of the present invention to provide a system and method for extracting a pigment for use in enhancing a color of grapefruit juice.
It is a further object to provide such a system and method for extracting a carotenoid pigment.
It is another object to provide such a system and method for extracting a carotenoid pigment that is water-dispersible.
It is also an object to provide such a system and method for extracting pigment without the use of enzymes or organic solvents.
It is an additional object to provide a system and method of enhancing the color of grapefruit juice.
These and other objects are achieved by the present invention, a system and method for extracting a color-enhancing pigment. The method comprises the steps of separating grapefruit into in-line pulp and juice and then separating the juice into clarified juice and retentate. At least one of the retentate and the in-line pulp is then homogenized to form a slurry, and the pigment is recovered from the slurry.
It should be noted that the extraction method of the present invention is accomplished without the use of enzymes or harsh organic solvents, but rather is an aqueous-based method.
The system of the present invention comprises means for carrying out the above steps, including an extractor and a finisher such as are known in the art to separate citrus fruit into in-line pulp and juice. An ultrafiltration unit is used to separate the juice into clarified juice and retentate. Homogenization is accomplished with applied pressure, and pigment recovery, by washing and centrifugation.
The features that characterize the invention, both as to organization and method of operation, together with further objects and advantages thereof, will be better understood from the following description used in conjunction with the accompanying drawing. It is to be expressly understood that the drawing is for the purpose of illustration and description and is not intended as a definition of the limits of the invention. These and other objects attained, and advantages offered, by the present invention will become more fully apparent as the description that now follows is read in conjunction with the accompanying drawing.